Just north of the Lehigh Valley, Pennsylvania's Slate Belt contains the richest slate
veins in the world and once produced more than two-thirds of America's roofing products.
The Big Bed quarry one of only two operating quarries left in the region, continues to
produce slate for pool tables and roofing. This place is truly out of the 19th century.
Antique looking machines cut huge sheets of slate. Water is used as a cutting fluid (see
picture below) and there is wet slime (mostly slate dust) everywhere.